Electronic circuit breakers are used in certain electrical systems for protecting branch electrical circuits that are coupled to an electrical power supply. Some such circuit breakers, such as for low voltage tripping applications (e.g., 100V to 600V), may include a tripping shaft that is mounted in a rigid frame. The tripping shaft includes multiple lever arms that are configured to interface with various tripping components of the circuit breaker, such as a maglatch actuator, interlock, or the like. Assembly of such tripping shafts has been quite complicated and time consuming. Such tripping shafts are typically spring biased so that upon actuation thereof, they may return to a common rotational orientation under a restoring force provided by a return spring. Assembly of the return spring to the tripping shaft can be quite difficult. Accordingly, there is a need for a tripping shaft and tripping assemblies that are easier to assemble and provide adequate spring bias to the tripping shaft.